Indeed, when viewed with a 20-inch scope at 175x, some of the diffuse plume structure
visible is suggestive of the appendages of some description of cosmic crustacean or starfish.
Related to the overall lower mixture density, it would appear that the RANS simulation produces a more diffuse (less dense) plume structure
than the LES simulation despite the fact that the input cone-angle is much smaller (9[degrees] compared to 25[degrees]).
Atema at the Marine Biological Laboratory in Woods Hole, the behavior of a robot told us something unsuspected about the plume structure (Grasso et al.
Their external sensors, borne on movable antennae, provide access to dynamic information associated with plume structures that is simply not available to vertebrates with internal noses.
The main emphasis was on the mixing process as it affected the plume structure.
In this way, the plume structure and the local meteorology can be described in sufficient detail to produce predictions in the neighborhood of the measured concentrations.
The most critical change in thinking has been an abandonment of diffusion models of odor plume structure as a way to examine stimulus concentration.
The earliest formulation of time-averaged plume structure applied to insect navigation was derived by Sutton (1953); it solves for the concentration C from a source emitting continuously at a rate J, for a point at a downstream distance r and angle [theta] from the midline of the plume:
The most detailed studies that have attempted to measure fluid dynamic conditions, odor plume structure, and resultant orientation behavior have involved moths, crabs, and lobsters.
Several studies have measured odor plume structure either in water or air to determine odor parameters that have the potential to be extracted and used by animals that navigate in odor plumes (Murlis, 1986, 1997; Murlis et al.
Although salt and ethanol diffuse differently than food odors at the molecular scale, we observed no visual differences in plume structure
between odor plumes and ethanol-salt plumes.
A stable plume structure
permits direct binary comparisons of chemical concentration inside and outside the plume, to guide movement lateral to flow.